The International Mobile Telecommunication—Advanced (“IMT Advanced”) vision of complementary interconnected access systems for the next generation mobile communication networks in International Telecommunication Union (“ITU”) foresees a seamless inter-working between the traditional wide area cellular mobile systems and local area systems. The latter is named to IMT-A nomadic local area concept that is built of wireless hot spots or local coverage. A long-term evolution/system architecture evolution (“LTE/SAE”) cellular operator may support IMT-A compliant local area systems by providing a local Internet protocol connectivity within a certain area (referred to as a “local IP breakout service area”) with roaming, with limited user mobility and Internet protocol session continuation (nomadic mobility). The local IP connectivity may cover a local zone in a city center or any limited geographical area, an enterprise network, or a home network wherein LTE radio coverage is available. At a minimum, the local IP breakout service area can be provided using one LTE cell/base station and may be expanded to a wide LTE coverage area in an operator's nationwide domain or public land mobile network (“PLMN”). The LTE/SAE service with roaming, global/inter-radio access mobility with IP session continuation may be overlapping and use the same cells/base stations that provide the local IP breakout service.
Normally, user equipment such as a mobile station is connected to the LTE/SAE network so that an SAE gateway provides the IP point of attachment. The selection of the SAE gateway happens during an initial attaching procedure wherein the user equipment is authenticated and authorized to use network services. The SAE gateway can be selected either from the visited public land mobile network or user equipment's home public mobile network depending on the roaming agreement between the operators. In the case wherein an SAE gateway is selected from the visited public land mobile network, there is a question of selecting a more localized SAE gateway than a more distant default SAE gateway for a “local IP breakout service” with roaming. For the purposes of the present discussion, however, it is assumed that a more localized gateway than the SAE gateway can be selected for the “local IP breakout service” such that default IP connectivity via the SAE gateway and a local gateway may be retained in parallel. This more localized gateway may reside even in the base station that is used for the given traffic.
It is desirable that the standard LTE/SAE initial attaching procedure should support selecting one user-plane (“U-plane”) anchor from the SAE gateway based on one access point name (“APN”) at a time (i.e., based on one set of settings used for a connection of user equipment to the Internet). An APN is an identity of an Internet network to which a mobile station such as user equipment can be connected, or the settings that are used for that connection. This may be referred to as a “single APN concept.” In the case wherein multiple active IP addresses/access point names are supported, it may cause a problem in the user equipment as there is uncertainty as to which IP address/access point name each application should select for an application level session. The selected access point name may be selected manually by the user equipment on every session initiation, or pre-configured into the user equipment per application. In the case wherein the same application uses multiple IP addresses/access point names, automatic selection rules may be employed by the user equipment.
There have been studies about an “Always Best Connected” concept wherein the user equipment is able to automatically select the best access for particular end-user services. (See, e.g., “‘Always Best Connected’ Enabled 4G Wireless World,” by O'Droma, et al., IST Mobile and Wireless Communications Summit, 2003, which is incorporated herein by reference.) This access technology selection is assumed to work based on pre-configured rules in the user equipment. The “Always Best Connected” concept may support using multiple IP addresses in the user equipment (i.e., network interfaces for each access technology may be associated with different IP addresses). The switching function between the alternative access technologies should not cause a problem in IP address binding to an application in the user equipment because only one access technology and its associated IP address should be in use at a time. Thus, this solution does not provide a solution for using multiple IP addresses bound to access point names within the same access technology, that would provide an improvement thereby from prior art solutions.
Thus, what is needed in the art is a system and method that allows user equipment to use an IP address/access point name for a local IP breakout service in LTE/SAE that is an alternative to the default user IP address/access point name for SAE bearer services via an SAE gateway that provides global roaming and mobility support. Additionally, what is needed in the art is an application for IP multi-homing in user equipment wherein multiple IP addresses can be associated with a single network interface using, for instance, an LTE radio system.